Bolt-anchor.



J. KENNEDY.

BOLT ANCHOR.

APPLICATION FILED JUNE 24, 1910.

Patented Jan. 1911.

WITNISSES:

JOSEPH KENNEDY, or NEW YoRK, N. if.

BOLT-ANCHOR.

Specification of'Letters Patent.

Patented Jan. 17, i911.

Application filed June 24, 1910. Serial No. 568,643.

To all whom it may concern:

undue amount ofthe metal being cut away Be it known that I, JOSEPH KENNEDY, a between the threads. citizen of the United States of America, and a resident of New York, county and State l oughly understood, I will now proceed to of New York, have invented certain new and useful Improvements in Bolt-Anchors, of which the following is a specilication, reference being had to the accompanying drawings, forming a part thereof.

My invention relates to improvements in bolt anchors of the character employed for obtaining anchorage in brick or stone walls or the like wherein the material is of a character not adapted to directly receive a threaded bolt.. v

My invention consists in a longitudinally segmental anchor interiorly threaded with a double thread whereby it is adapted for luse with a twin thread bolt. e

I have found by experience in the past that when a bolt having the ordinary single thread is employed in a longitudinally segmental anchor correspondingly threaded in the interior thereof, there is a tendency of the bolt to drift either to one side or the other along the line of division between the segments. This has been a source of much annoyance in that it not only distorts and injures the f anchor, but it-xaiiects the alinement of the bolt and reduces the efficiency of the device as a means for securing articles lirmly in position. These ditiicultie's are entirely obviated by using a double or twin thread bolt and anchor threaded correspondingly thereto, by reason of the fact that the threads voperate uniformly upon opposite sides of the device. I have also found that by reason of the fact that the thread projections are exactly opposite to each other in a double or twin thread bolt, the wedge action is more powerful and more effective than in asingle thread wherein the thread projectionsupon opposite sides are necessarily in staggered relation. rBhe employment of twin or double threads is further advantageous in that the bolts can be inserted and removed more rapidly.

My invention also consists in constructing the walls of the thread depressions and projections upon substantially vertical lines upon one sidethereof and oblique on the other side thereof, whereby the Obliquity of the threads is upon one side thereof only. Bythis 'means a flatter surface may be pre sented to the threads of the bolt without an i l l In order that my invention may be thordescribe an embodiment thereof, having reference to the accompanying drawings illustrating the same, and will then point out the novel features in claims.

In the drawings: Figure 1 is a view in central transverse section through a` bolt anchor constructed in accordance with my invention, showing the same inserted in an opening in a wall and with a bolt partly in serted therein. Fig. 2 is a View in longitudinal section therethrough at right angles to the point of view of Fig. l, the bolt being shown as completely inserted and the anchor segments expanded. Fig. 3 is a transverse sectional view through the anchor and bolt upon the line 3-3 of Fig. 1. Fig. 4 is an enlarged view in longitudinal section through a portion of the bolt. Fig.

5 is a view in cent-ral longitudinal section.

through a slightly mo'dilied form of anchor showing a counter sunk head wood screw in connection therewith. Fig. 6 is a transverse sectional view upon the line (S-G of the scri-:w and anchor shown in Fig. Referring first of all to the anchor shown in Figs. l to 3 inclusive the same comprises a shell 10 longitudinally divided throughout the greater portion of its' length by means of slots 11, whereby the said shell, as a whole, comprises in effect two longitudinal tubular segments. This shell has a longitudinal bore, the forward end 12 of which preferably of slightly larger diameter than the remaining portion whereby to form an open throat to receive and guide vthe bolt to be enployed therewith, the remaining portion of the bore being interiorly threaded, as at 13, with a double screw thread, the inner extremity of the shell being conveniently inwardly convergent as is shown at 14. Preferably the threads have one wall as 15 substantially aty thebolt is driven home it expands the inner ,end of the anchor, forcing the segments apart. In this form of anchor the shell is preferably made of a soft metal such as load or lead composition, and the segments will be bent and swag-ed to conform to the con-y figuration of the hole by the bolt as it is forced inward, as-will be well understood by'tliose familiar with this art. The double threads acting uniformly on both sides of the axial center of the bolt and anchor will have the tendency to apply a uniform wedging action in both directions thereby obviatingany tendency of the bolt to drift, and in addition thereto the'form of the threads, in

. which the inclination is substantially all l the anchor lirmly in position.

may be had to Fig. et which shows upon anupon one side of lines at right angles to the axis of the bolt and anchor will result in a powerful wedging action whereby to secure 'Reference enlarged scale, the relative -positions of the opposite threads and substantially the vcontour thereof.

It will of course benndersteod that-in the broad aspect of-my invention I a'n n# n0 Way limited to the class of anchor shell I einploy,

lor the material of which 'it is made, or the manner in which it is formed, and in Figs. 5 and 6 I have shown in longitudinal Vand transverse section an anchor longitudinally divided from end to end into two parts; the `segments whereof are made of hard metal such as brass or iron. The two sections may be held together by any suitable means as by means of a spring clip 19. I have shown this particular 'l'orin of shell in combination with a counter sunk head wood screw 20 of` ordinary construction except that it has twin threads 2l of the form previously described, and as the shank of this forni of screw is usually longitudinally tapered, I have cui'- respondiuglv tapered the bore of the shell as at 22, clear fronr the inner end up to the open throat.

It will be understood that while for pracA tical purpose a double thread will be the best form, it will be noted that a similar action and disposition' of the thread projections upon the opposite sides thereof, would be attained by threads formed as multiples of two, and hence while the description herein is, for clearness, specific to two threads, it will equally apply to quadruple or sextuple threads.

What I claim is:

1. In a bolt anchor the combination with an interiorly threaded shell, the thread de- 'pressions upon opposite sides thereof in a central longitudinal plane therethrough, being in direct lines with each other in the said plane and at rightvangles to the aXis of the shell, of a correspondingly threaded bolt for co-action therewith. i

2. In a bolt anchor the combination with a tubular shell composed of longitudinal segments, the said shell having an inwardly convergent bore therethrough provided with helical projections 'and depressions constituting a double thread, of a correspondingly .doiible threaded bolt for co-action therewith.

the 'opposite side are oblique thereto, of

correspondingly threaded bolt for co-action therewith. i n

4, In a bolt anchor 'the combination with an expansible shell having a longitudinal bore tlhierethrougl'i and provided with helical depressionsand projections constituting double screw threads, 'the walls whereof upon one side are substantially vertical and upon the opposite side are oblique thereto, of a cfnrespondingly double threadedbolt for covactintherewith.

JQSEPI-I KENNEDY.

Witnesses' JACOB IsLnn, lWM. Il'. lilaisriiuii'r.

sov 

